Solid freeform printers (SFFPs) have recently become very popular because they promise the ability to create three-dimensional objects easily from computer generated models. Indeed, because of the ease of use of SFFPs, SFFPs are increasingly being marketed towards consumers for in-home use. However, current SFFPs suffer from a number of drawbacks. Although, there are different variants of SFFPs, one common type uses a technique referred to as fused deposition modeling. In fused deposition modeling, a target material is melted within the nozzle of the 3d printer, and dispensed in a stream of liquid layer-by-layer until the desired object is created. Because the target material is in a melted state within the nozzle, eventually due to build-up and other factors, the nozzles often become clogged with target material. Additionally, because the target material is deposited in layers, objects printed using fused deposition modeling often show visible layering and do not have desirable shear-strength.
Another common type of SFFP uses a process known as laser sintering, or heat sintering. In these types of SFFPs, a powder is deposited for each layer of the printed object, and cured layer-by-layer with a heat source or a laser until the printed object is complete. Similarly, another common type of SFFP uses a process known as stereolithography (SLA), which deposits a resin layer-by-layer that is curable via ultraviolet light.
SFFPs also commonly take a long time to print objects. One reason for this is because they have single heads that dispense the target material onto the printed object. Accordingly, such SFFPs are limited by how fast they can move the heads and dispense the material from the heads. One reason why SFFPs have single heads is because streams of molten material, powders, or resins are not controllable enough to have multiple heads dispensing material at once. Other SFFP technologies based on piezo and thermal inkjet technology allow uniform material strength and color printing but must dispense material in low viscosity liquid form. Color bleed is also a problem with liquids.
The invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the reference number